I got similar situation on my first baby. I even need to eat painkiller and many other pills that I don't remember. Even need MRI to check. Bcoz it worsen till I can't even write. Then, cannot tahan already. Doctor say really cannot carry your child anymore if I want to get better. So, I find ways to play with my baby so I need not carry him. Then, I found that he like to play with his blanket. So, I'm saved.

Try to find other ways to entertain your baby besides carrying. 

TS: Find a good 跌打 (chinese physiotherapist), rather than get tonnes of medicine. This case, meds can't heal you. Also, a tukang urut bidan (I think that's what they call) for your wife. My area, I go for malay/siamese (thai style) really good. Can help ease the pain.

Try to observe what catches your babies attention. I got my son on a baby walker around 5+ months since he likes to jump. When I hold him, he just jumps non-stop. I counted once you know...1000 times! I yg tak tahan. I stopped him, he's not even tired yet.

What else I did:

Lay down a thin big mattress on the floor. Play toss around. Make it exciting. Boxing with teddy bear...let him punch also. Play inside blanket or a tent. Some more you can lie down more...hahaha

And many more...you'll get more creative from there